This invention relates to the field of rotating drum debarkers for removing bark from logs and similar roundwood. More particularly, this invention relates to an improved means and/or method for more efficiently removing wood from the rotating drum debarker by using an outfeed spool.
Apparatuses and methods for debarking wood have been described in the prior art. For example, Applicant, in U.S. Pat. No. 5,005,621, described an improved rotating drum debarker for removing bark from logs and similar roundwood, particularly long roundwood, which included a conveyor chute to feed logs to the drum, wherein the drum included lifters and reinforcing rings where the reinforcing ring at the inlet and/or outlet of the drum had an inside diameter greater than the free inside diameter of the drum in order to improve the movement of logs through the drum. However, no means for aggressively removing the logs from the drum debarker were provided as does the present invention. The fact that there is no aggressive means to remove the logs from the drum debarker is a major disadvantage of this type of prior art drum debarker because the logs tend to become entangled with each other as they travel through and begin to exit the drum debarker and do not exit the drum debarker in as efficient a manner as would be provided by the present invention. This deficiency in the prior art is remedied by the present invention.
In a drum debarking system, logs are fed into the drum debarker horizontally via a power feeding system. As the power feed chain bed moves stems to the drum, a constant push is applied to the wood already in the drum debarker which forces debarked logs out into the drum discharge conveyor and then the chipper feed area. The power feed allows higher rates of production and more efficient debarking.
The drum debarker is supported by a metal framework. Drum speed is 0-12 rpm and has approximately 11% bark slot area. The drum can be operated in either clockwise or counter clockwise rotation. In a two drum arrangement, both drum shells are substantially identical and fully symmetrical so that they can be wear rotated for longer life.
The drum discharge conveyor incorporates the present invention, i.e., the Drum Debarker Outfeed Spool, which helps pull the debarked stems out of the drum debarker, and thereafter the drum discharge conveyor helps in singulation of wood to the chipper.
Controls for the plant are located in a stationary control cab positioned at a location where the operator can use line of sight to view debarking of wood in the drum and also direct the flow of wood into the chipper. A remote/electric controlled hydraulic loader assists the operator in handling problem logs.
Chipping is handled by a chipper that is driven by dual 600 hp electric motors. The motor shafts transmit torque to the chipper shaft via a dual belt drive. Soft start assemblies accomplish getting the motors up to speed within the local power company's demands.
Rotating drum debarkers of the type having lifters in the form of circumferentially spaced apart projections extending inwardly from the inner surface of the drum shell are well known. A typical debarking drum takes the form of a relatively thin cylindrical shell with the lifters welded to the inside of the shell, and with slots in the wall of the shell in the regions between the lifters for discharging removed bark from the drum. The lifters extend the length of the shell and serve to stiffen and reinforce the shell.
A typical lifter takes the form of a length of U,V, or L-shaped angle iron or channel with the ends of both its legs welded to the inside of the shell so the tip or peak of the lifter points toward the axis of the drum. A stiffening or reinforcing ring is secured to each end of the drum, and the ends of the lifters are usually welded to the inner side surfaces of these rings.
Thus, the lifters cooperate with the shell and the reinforcing rings to provide a beam reinforced skin structure which is quite strong even though the shell skin or side wall of the drum is relatively thin.
In the past, roundwood was cut to relatively short lengths for drum debarking because the short lengths were easy to handle with the available equipment. Tile trend today is toward debarking of tree length logs, and to provide long lengths which can be chipped more efficiently for pulpwood use, where the logs after debarking, are found to be unsuitable for use as lumber.